|   | 
Details
   web
Records
Author Mercier, A.; Ycaza, R.; Hamel, J.
Title Long-term study of gamete release in a broadcast-spawning holothurian: predictable lunar and diel periodicities Type Journal Article
Year 2007 Publication Marine Ecology Progress Series Abbreviated Journal Mar. Ecol. Prog. Ser.
Volume 329 Issue Pages 179-189
Keywords Spawning; Periodicity; Lunar cycle; Reproductive synchrony; Holothurians; Echinoderms; Isostichopus fuscus
Abstract Annual and monthly patterns of gamete release by the sea cucumber Isostichopus fuscus on the coast of Ecuador were studied to determine the proximal spawning cue and variations in reproductive output throughout the year. Several hundred newly collected individuals were monitored nearly every month for 4 yr. I. fuscus displayed a lunar spawning periodicity: 0.7 to 34.9% of individuals consistently spawned 1 to 4 d after the new moon. Spawning mostly occurred within one evening; however, some gamete release was often recorded over 2 to 4 consecutive evenings. Individuals maintained in captivity for several months retained their spawning periodicity and timing with the lunar cycle. Conversely, newly caught individuals that were shaded from the moonlight did not spawn, thus demonstrating the apparent lack of endogenous rhythms and prevalence of lunar luminance over other cues (i.e. tidal cycle, fluctuations in barometric pressure). On a spawning night, males typically initiated gamete release around sunset; females spawned just after the peak male broadcast. The percentage of spawning individuals was higher and a greater overlap between male and female peak spawning activity was observed during clear conditions compared with overcast conditions. The gonads of individuals that did not spawn in a given month showed a variety of maturity levels, including post-spawning, growth and mature gametogenic stages. Hence, the individual reproductive cycle is apparently longer than the monthly spawning periodicity observed at the population level, enabling I. fuscus populations to be reproductive year round.
Address
Corporate Author Thesis
Publisher Place of Publication Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0171-8630 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 104
Permanent link to this record
 

 
Author Kelber, A.
Title Light intensity limits foraging activity in nocturnal and crepuscular bees Type Journal Article
Year 2005 Publication Behavioral Ecology Abbreviated Journal Behavioral Ecology
Volume 17 Issue 1 Pages 63-72
Keywords bees; eyes; foraging; insects; ocelli; sensitivity; visual ecology
Abstract A crepuscular or nocturnal lifestyle has evolved in bees several times independently, probably to explore rewarding pollen sources without competition and to minimize predation and nest parasites. Despite these obvious advantages, only few bee species are nocturnal. Here we show that the sensitivity of the bee apposition eye is a major factor limiting the ability to forage in dim light. We present data on eye size, foraging times, and light levels for Megalopta genalis (Augochlorini, Halictidae) in Panama, and Lasioglossum (Sphecodogastra) sp. (Halictini, Halictidae) in Utah, USA. M. genalis females forage exclusively during twilight, but as a result of dim light levels in the rain forest, they are adapted to extremely low intensities. The likely factor limiting their foraging activity is finding their nest entrance on return from a foraging trip. The lowest light intensity at which they can do this, both in the morning and the evening, is 0.0001 cd m−2. Therefore, they leave the nest at dimmer light levels in the morning than in the evening. Lasioglossum (Sphecodogastra) foraging is limited by light intensity in the evening, but probably by temperature in the morning in the temperate climate of Utah. We propose that the evolution of nocturnality in bees was favored by the large variance in the size of females.
Address
Corporate Author Thesis
Publisher Place of Publication Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1045-2249 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 119
Permanent link to this record
 

 
Author Bennie, J.; Davies, T.W.; Inger, R.; Gaston, K.J.; Chisholm, R.
Title Mapping artificial lightscapes for ecological studies Type Journal Article
Year 2014 Publication Methods in Ecology and Evolution Abbreviated Journal Methods Ecol Evol
Volume 5 Issue 6 Pages 534-540
Keywords light pollution; urban ecology; landscape ecology; diurnal; nocturnal; night; light
Abstract Artificial illumination of the night is increasing globally. There is growing evidence of a range of ecological impacts of artificial light and awareness of light pollution as a significant environmental issue. In urban and suburban areas, complex spatial patterns of light sources, structures and vegetation create a highly heterogeneous night-time light environment for plants and animals.

We developed a method for modelling the night-time light environment at a high spatial resolution in a small urban area for ecological studies. We used the position and height of street lights, and digital terrain and surface models, to predict the direct light intensity at different wavelengths at different heights above the ground surface.

Validation against field measurements of night-time light showed that modelled light intensities in the visible and ultraviolet portions of the spectrum were accurate.

We show how this model can be used to map biologically relevant lightscapes across an urban landscape. We also illustrate the utility of the model using night-time light maps as resistance surfaces in the software package circuitscape to predict potential movement of model nocturnal species between habitat patches and to identify key corridors and barriers to movement and dispersal.

Understanding the ecological effects of artificial light requires knowledge of the light environment experienced by organisms throughout the diurnal and annual cycles, during periods of activity and rest and during different life stages. Our approach to high-resolution mapping of artificial lightscapes can be adapted to the sensitivity to light of different species and to other urban, suburban, rural and industrial landscapes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041210X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 171
Permanent link to this record
 

 
Author van Geffen, K.G.; van Grunsven, R.H.A.; van Ruijven, J.; Berendse, F.; Veenendaal, E.M.
Title Artificial light at night causes diapause inhibition and sex-specific life history changes in a moth Type Journal Article
Year 2014 Publication Ecology and Evolution Abbreviated Journal Ecol Evol
Volume 4 Issue 11 Pages 2082–2089
Keywords Caterpillars; development time; diapause; light pollution; pupal mass; pupation; light exposure; light pollution; biology; moths; insects; Mamestra brassicae
Abstract Rapidly increasing levels of light pollution subject nocturnal organisms to major alterations of their habitat, the ecological consequences of which are largely unknown. Moths are well-known to be attracted to light at night, but effects of light on other aspects of moth ecology, such as larval development and life-history, remain unknown. Such effects may have important consequences for fitness and thus for moth population sizes. To study the effects of artificial night lighting on development and life-history of moths, we experimentally subjected Mamestra brassicae (Noctuidae) caterpillars to low intensity green, white, red or no artificial light at night and determined their growth rate, maximum caterpillar mass, age at pupation, pupal mass and pupation duration. We found sex-specific effects of artificial light on caterpillar life-history, with male caterpillars subjected to green and white light reaching a lower maximum mass, pupating earlier and obtaining a lower pupal mass than male caterpillars under red light or in darkness. These effects can have major implications for fitness, but were absent in female caterpillars. Moreover, by the time that the first adult moth from the dark control treatment emerged from its pupa (after 110 days), about 85% of the moths that were under green light and 83% of the moths that were under white light had already emerged. These differences in pupation duration occurred in both sexes and were highly significant, and likely result from diapause inhibition by artificial night lighting. We conclude that low levels of nocturnal illumination can disrupt life-histories in moths and inhibit the initiation of pupal diapause. This may result in reduced fitness and increased mortality. The application of red light, instead of white or green light, might be an appropriate measure to mitigate negative artificial light effects on moth life history.
Address 1 Nature Conservation and Plant Ecology Group, Wageningen University, Droevendaalsesteeg 3a, P.O. box 47, 6700 AA, Wageningen, the Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-7758 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 306
Permanent link to this record
 

 
Author Henn, M.; Nichols, H.; Zhang, Y.; Bonner, T.H.
Title Effect of artificial light on the drift of aquatic insects in urban central Texas streams Type Journal Article
Year 2014 Publication Journal of Freshwater Ecology Abbreviated Journal Journal of Freshwater Ecology
Volume 29 Issue 3 Pages 307-318
Keywords light pollution; stream ecology; urban ecology; drift; abiotic factors; Baetidae; Chironomidae; insects; Texas; Simuliidae; Edwards Plateau; light at night; ecology
Abstract Light pollution can reduce night time drift of larval aquatic insects in urban streams by disrupting their circadian rhythms. Previous studies on larval insect drift show that disruption in drift leads to changes in reproduction as well as intraspecific and interspecific interactions. The purpose of this study was to conduct a preliminary investigation into the effects of extreme artificial light on insect drift in urbanized, high clarity spring systems of the karst Edwards Plateau, TX. We quantified taxa richness, diversity, and abundance in aquatic insect night time drift under two treatments (ambient night time light and artificial light addition) and among five streams using a paired design. Richness and diversity of drifting aquatic insects were similar between treatments but abundance was 37% less in the light addition treatment than that of the control. Effects of light addition on mean abundance was more notable in large streams with a 58% decrease in Simuliidae (compared to that of the control) and 51% decrease in Baetidae. Reduced drift from light addition suggests the potential of artificial lighting disrupting insect drift and consequently community structure. Results of this experiment support a growing body of knowledge on how urbanized systems influence stream communities.
Address Department of Biology/Aquatic Station, Texas State University, San Marcos, TX, USA
Corporate Author Thesis
Publisher Taylor & Francis Place of Publication Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0270-5060 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 312
Permanent link to this record